Dividing head for grinding and other machines



Jam. 16, i923,

H.`F. L. ORCUTT. DWv|D|Ns HEAD FOR GRnNolNG AND OTHER MACHINES.

FlLED JULY 25. 1921.

lng@ @zwi/3a@ lf., Ff l2 @E HARRY FRED LEE ORCU'IT, 0F BIRMINGHAM, ENGLAND, ASSIGNOR TO THE GEAR GRINDING COMPANY LIMITED, OF BIBMINGHAIE, ENGLAND.

DIVIDING HEAD FOR GRINDING AND OTHER MACHINES.

Application filed July 25,

To all whom t may concern Be it known that I, HARRY FRED Lnn OR.- CUTT, a subject of the King of Great Britain and Ireland, residing at Anne Road, Handsworth, in the city of Birmingham, England, haveinvented certain new and useful Improvements Relating to Dividing Heads for Grinding and Other Machines, of which the following is a specification.

This invention relates to machines for grinding gear wheel teeth or shaft splines, and for like work involving the use of a grinding wheel whose periphery is accurately shaped to a definite form. In such machines it is usual to hold the workstationary during the grinding operations, and to impart an angular movement to the work intermittently for the purpose of subjecting` different parts to the action of a grinding wheel` which is reciprocated relatively to the work.

Whilst primarily intended tor grinding machines, the invention is also applicable to other machines, such as gear cutting machines in which intermittent angular movements of the work are required.

The object of the present invention is to provide an improved dividing head whereby the necessary high order of accuracy in the said intermittent angular movements of the work can be obtained in a convenent manner.

The invention comprises the combination with the work spindle, of a disc having peripheral notches corresponding to the required angular movements of the work, a spring controlled locking pawl for engaging the said notches in turn and locking the disc,V an arm receiving motion from a crank and provided with a paw] for actuating the disc, and a cam on the arm for disengaging the locking pawl prior to each movement of the disc The accompanyin drawing illustrates dividing head mechanism constructed in accordance with this invention.

` In carrying the invention into eliect as shown, a relatively large disc a, is secured to one end of the work spindle b. This disc is formed with notches caround its periphery at intervals corresponding to the number of wheel teeth, shaft splines, or the like on the work piece or pieces to be ground or otherwise treateclz Each of these notches is en? 1921. Serial No. 487,473.

gaged in turn by a pawl CZ controlled by a spring c and carried on an'arm 7 which is freely mounted coaXially with and alongside of the disc. On an adjacent portion or" the lixed frame or case is pivoted a locking pawl g adapted to accurately iit the disc notches and to engage each in turn for the purpose of rigidly locking the disc, this pawl being held in its operative position by a spring 72, acting through a pressure piece c' on the outer end oi" the pawl g. To lift the pawl out of action the arm above mentioned is utilized, its outer end being shaped as shown at j to serve as a cam for engaging the pawl through the medium of a projection 7c on theI pawl.

Motion is given to the arm by al slide Z which is actuated through a connecting rod m from an adjustable-throw crank a, the latter receiving its motion at proper intervals from some other suitable part oi' the grinding or cutting machine. Preferably the slide is of cylindrical form and arranged to .reciprocate in a cylindrical guide o the underside of the latter being slotted to permit the passage through it from the slide oi" a fork piece 79 which engages a projecting roller g or the like secured to one side of the arm f.

Adjacent to the slide is arrangefil a bell crank lever fr' pivoted on the 'case or trame of the machine. @ne end oit this lever acts on the outer end of a cup s containing the spring 7L and slidable over the pressure piece z'. The other end of the lever is iitted with an adjustable screw stop t which can coact with an abutment 'a on the slide. During a small portion of thevmovement of the slide when it is completing its traiferse from left to right, the abutment strikes against the stop and causes the opposite end of the lever to press on the cup s, the pressure being transmitted through the spring and pressure piece to the pawl g and serving to fonce the tapered end of the pawl firmly into the adjacent notch in the disc.v This insures accurate positioning of the disc. Preferably the movement given to the disc by the other paw] (l is slightly short oit that required to bring the disc at each operation into .the proper position, the linal positioning being eected by the action of the lever r on the pawl g. During the movement of the slide from right to lett, the lever r is lett tree so that itxoifvifers fr iokhinilirztnxae to the raising of the pztvvl g outof engagement with the disc by the arm f.

In operation the Aarm f moves under the actionof the crank first in one direction and then in the other. 'During1 the movement from right to left, lthe calinon the givin lifts the pewl g out of action` and the erin traverses the peivl IZ to the nent Ynotch over the periphery of the disc. In the return 0f the arm' frQIn ylei-:t to right the padvl d ymoves :the .disc through :an Aangular distance equal l,to the pitch i of Athe notches, or nearly so.y `and the slide Zibyzopeneting on the lever vgtceuses :the final positioning va-ndsecnring,of the disc throiirghgthe -pffiwl g, .Ithe letter having` immediate-ly prior I,to the action of .this ylever been allowed by ithe erm ,to .drop into lvthe fil-Cljacent .lnctch in .the disc `under its own weight By this invention l ,am @ble t0 provide a robustend ,rigid dividing head which. vpermits of the desired accuracy of ,operation ,to be obtgtined in i very :simple manner. When it is desired Ato ,provide van adjustable connection between the disc and its spindle, a collar o issecnred to the Ispindle eind connection ,with ,the `disc isfected by adjustable s crewsrw acting` on la projection m secured ,to thedisc.

Having-,thus ,described my invention what I claim as new .and .desire tto secure .by Letters Patent ,is :e

.l- In dividing' heads ,for ,impmrtng ,ensuler movements .t0 e Werk piece; .i'fhecmbnetion of e Work spindle@ dis@ having ne ripherel. notches conresponding to the reqiiired zinvular movements of the Work spinthe disc'. a `cam 0n the .arm for disenga-gingthe lockingfpawl prior to each movement of the disc, A. slide V'for actuating the arm, a

`cratnk.for`1jeciproeating the slide, a lever adjacent to the locking pzuvl, and a spring' and thrust piece between the seid lever and flocking paAvl, the lever being` actuated by the .slide for pressing the locking` pawl intc its Qpenzitive .position7 substantially as described.

2. In dividingheads for imparting engular movements .to a Work *piece7 the combination .of :i yWerl; spindle, e disc having peripheral notches onseid spindle, a locking pawl l.engf igeable` with the ldisc notches, a rocking erin, a `1in-voted Vpjuvl on the arm and vlso engelgeable with Vthe disc notches for actuating `the vdisc, e spring .operating on the disc actuating .peWL an ,erin actuating slide, a lcrank for reciproeatingthe slide, e

cem on `the verm .for disengaging` the lock- ,ing pmvl, 2L lever adjacent to the locking .puvlJ lend spring and thrust piece between Ythe seid :leveifaiid lockinglmivl, the lever being Ezuitiluite-d by the slide `for pressing the locking pawl into its operative position,.mib stantielly as described.

In V.testimony whereof I have signed my neme to this specification.

HARRY FRED LEE oRcUTT. 

